Hi Everyone, Been a long time reader of the forum, and have learn a lot. So here's my first post and first question. I've been agonizing over buy a new lens, and I've narrowed it down to the EF-S 17-55. Has anyone tried using this lens for action photography? Like kids and toddlers running around? I'd like to have this lens for low light, and situations where I can get away without flash, and still capture sharp kids in motion. Any thoughts? Alternate lenses? thanks in advance!